1. Field of the Invention
This invention relates to a seat track assembly for a seat of a motor vehicle. More particularly, the invention relates to a reinforcement bracket for controlling deformation and preventing separation between upper and lower tracks of a seat track assembly during a motor vehicle impact.
2. Description of the Related Art
A motor vehicle includes a plurality of seats positioned throughout a passenger compartment for supporting motor vehicle occupants. Each seat includes a generally horizontal seat cushion, and a generally upright seat back operatively coupled to the seat cushion to allow for pivotal adjustment of the seat back relative to the seat cushion between a plurality of reclined seating positions.
A seat track assembly is typically mounted to a bottom surface of the seat cushion and provides fore and aft movement of the seat within the motor vehicle. The seat track assembly includes a lower track secured to a floor of the motor vehicle and an upper track slidably engaging the lower track. The upper track is fixedly secured to the bottom surface of the seat cushion to allow for sliding movement of the seat along the lower track. A locking mechanism is operatively coupled between the upper and lower tracks for selectively locking the position of the upper track relative to the lower track. The locking mechanism is either a continuously engaged lock utilizing a lead screw positioner, or a non-continuously engaged lock utilizing a rack of teeth lockingly engagable with apertures formed in the lower track. The occupant actuates or unlocks the locking mechanism to adjust the seat to an optimal pedal and steering wheel position.
During a motor vehicle impact, loads associated with the weight of the seat and the occupant are transferred to the floor via the seat track assembly. This load transfer causes the upper and lower tracks to move away from one another, causing the seat track assembly to deform. As a result of this deformation, servicing of the seat track assembly is required to allow for the sliding movement of the upper track, and with it the seat, along the lower track.
U.S. Pat. No. 5,961,089 to Soisnard discloses a seat track assembly including a retention part for reducing the amount of separation between an upper track and a lower track during a motor vehicle impact. The seat track assembly includes the lower track fixedly secured to a floor of a motor vehicle and the upper track, which is movable relative to the fixed lower track, supporting a seat cushion thereabove. The upper track is U-shaped and includes two spaced apart vertical flanges extending downwards from a generally horizontal wall. The retention part is located proximate to a rear portion of the lower track. The retention part includes a first flange abutting a bottom part of the lower track and attached thereto by a rivet, and a second flange extending vertically from the first flange to a position between the spaced apart vertical flanges of the upper track. The second flange includes a pointed tooth extending out from each side thereof towards the spaced apart vertical flanges of the upper track. When the upper track is subjected to a high upward load, for example, during a motor vehicle impact, the upper track is moved upwards. As a result, the spaced apart vertical flanges of the upper track move toward one another until each of the spaced apart vertical flanges comes into contact with one of the pointed teeth. The pointed teeth bite into the spaced apart vertical flanges and are anchored thereto, thus preventing any further upward movement of the upper track relative to the lower track.